IBM USB keyboard with TrackPoint: how to adjust sensitivity

I connect the IBM USB keyboard with TrackPoint (UltraNav) to my Lenovo W510 using Windows 7. How can I adjust the sensitivity of the external TrackPoint? In control panel > mouse settings, I can only adjust settings of the onboard TrackPoint. Is this a driver issue, or I did it wrong? I tried downloading different drivers but none allows me that. Current drivers I use: